Generic Name: mercaptopurine (mer KAP toe PURE een)
Brand Name: Purinethol, Purixan
What is Purinethol (mercaptopurine)?
Mercaptopurine is a cancer medication that interferes with the growth and spread of cancer cells in the body.
Mercaptopurine is used to treat certain types of leukemia. Mercaptopurine is sometimes given with other cancer medications.
Mercaptopurine may also be used for purposes not listed in this medication guide.
What is the most important information I should know about Purinethol (mercaptopurine)?
You should not use mercaptopurine if you have ever used mercaptopurine or thioguanine (Tabloid) and they were not effective in treating your condition.
Some people using mercaptopurine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal.
Call your doctor at once if you have symptoms of lymphoma, such as: fever, night sweats, weight loss, tiredness, feeling full after eating only a small amount, pain in your upper stomach, easy bruising or bleeding, dark urine, or jaundice (yellowing of the skin or eyes).
What should I discuss with my healthcare provider before taking Purinethol (mercaptopurine)?
You should not use mercaptopurine if you are allergic to it, or if you have ever used mercaptopurine or thioguanine (Tabloid) and they were not effective in treating your condition.
Some people using mercaptopurine have developed a rare fast-growing type of lymphoma (cancer). This condition affects the liver, spleen, and bone marrow, and it can be fatal. This has occurred mainly in teenagers and young adults using mercaptopurine or similar medicines to treat Crohn's disease or ulcerative colitis.
However, people with autoimmune disorders (including rheumatoid arthritis, Crohn's disease, ankylosing spondylitis, and psoriasis) may have a higher risk of lymphoma. Talk to your doctor about your individual risk.
To make sure mercaptopurine is safe for you, tell your doctor if you have:
any type of viral, bacterial, or fungal infection; or
ulcerative colitis (treated with mesalamine, sulfasalazine, or similar medicines).
Do not use mercaptopurine if you are pregnant. It could harm the unborn baby. Use effective birth control, and tell your doctor if you become pregnant during treatment.
It is not known whether mercaptopurine passes into breast milk or if it could harm a nursing baby. You should not breast-feed while taking mercaptopurine.
How should I take Purinethol (mercaptopurine)?
Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Shake the oral suspension (liquid) well just before you measure a dose. Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.
Mercaptopurine can lower blood cells that help your body fight infections and help your blood to clot. Your blood will need to be tested often. Your kidney and liver function may also need to be checked. Your cancer treatments may be delayed based on the results of these tests.
Store at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking Purinethol (mercaptopurine)?
Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.
This medicine can pass into body fluids (urine, feces, vomit). Caregivers should wear rubber gloves while cleaning up a patient's body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.
Do not receive a "live" vaccine while using mercaptopurine, and avoid coming into contact with anyone who has recently received a live vaccine. There is a chance that the virus could be passed on to you. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.
Purinethol (mercaptopurine) side effects
Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using mercaptopurine and call your doctor right away if you have any of these symptoms of lymphoma:
fever, night sweats, weight loss, tiredness;
feeling full after eating only a small amount;
pain in your upper stomach that may spread to your shoulder;
easy bruising or bleeding, pale skin, feeling light-headed or short of breath, rapid heart rate; or
nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Also call your doctor at once if you have:
signs of infection (fever, swollen gums, painful mouth sores, pain when swallowing, skin sores, cold or flu symptoms, cough, trouble breathing);
unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
severe nausea, vomiting, or diarrhea;
pain or burning with urination; or
bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.
Common side effects may include:
nausea, vomiting, loss of appetite;
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
See also: Side effects (in more detail)
What other drugs will affect Purinethol (mercaptopurine)?
Tell your doctor about all medicines you use, and those you start or stop using during your treatment with mercaptopurine, especially:
sulfamethoxazole and trimethoprim (Bactrim, Cotrim, Septra, SMX-TMP or SMZ-TMP);
warfarin (Coumadin, Jantoven); or
drugs that weaken the immune system such as cancer medicine, steroids, and medicines to prevent organ transplant rejection.
This list is not complete. Other drugs may interact with mercaptopurine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.
More about Purinethol (mercaptopurine)
- Other brands: Purixan
Related treatment guides
Where can I get more information?
- Your doctor or pharmacist can provide more information about mercaptopurine.
- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2012 Cerner Multum, Inc. Version: 9.06.
Date modified: January 10, 2017
Last reviewed: October 06, 2015